Method and device for operating a fuel cell system
AssigneeMTU Mortoren-und Turbinen-Union
InventorsGerhard Huppmann, Peter Kraus
Life of this patent
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Abstract
The invention provides a method and apparatus for controlling gas circulation in a fuel cell system in which a stack of fuel cells is surrounded by a protective housing. According to the invention, used cathode gas and burnt combustion gas from the fuel cell stack directly into the interior of a protective housing which surrounds the fuel cell stack. A blower which is arranged inside the housing causes the used cathode gas to mix with the burnt combustion gas and recirculate to the cathode input of the fuel cell stack, where it is further with fresh gas from the exterior.
Claims18
A method for operating a fuel cell system of the type in which fuel cells arranged in a stack are surrounded by a protective housing, with an anode inlet for supplying combustion gas to the anodes of the fuel cells, an anode outlet for carrying the burnt combustion gas away from the anodes, a cathode inlet for supplying cathode gas to the cathodes of the fuel cells, and a cathode outlet for carrying away the used cathode gas from the cathodes, with the combustion gas being supplied to anode inlet by a combustion gas inlet device which provides a seal with respect to the interior of the protective housing, said method comprising the steps of:
- discharging used cathode gas from cathode outlet inside the protective housing;
- causing said used cathode gas to circulate back to the cathode inlet in the interior of the protective housing;
- discharging burnt combustion gas from anode outlet inside the protective housing;
- mixing said burnt combustion gas with the cathode gas stream circulating inside protective housing;
- and replacing a portion of the gas mixture circulating inside protective housing with fresh gas from outside said housing.
A gas circulation arrangement for a fuel cell system of the type in which fuel cells arranged in a stack are surrounded by a protective housing with an anode inlet for adding combustion gas to the anodes of the fuel cells, an anode outlet for carrying away the burnt combustion gas from the anodes, a cathode inlet for adding cathode gas to the cathodes of the fuel cells, and a cathode outlet for carrying away the used cathode gas from the cathodes, as well as with a combustion gas inlet device which provides a seal with respect to the interior of protective housing for supplying the combustion gas to anode inlet, said arrangement comprising:
- a cathode outlet of the fuel cell stack which opens to discharge used cathode gas inside the protective housing;
- a blower device provided inside the protective housing for causing the used cathode gas to circulate to the cathode inlet of the fuel cell stack inside protective housing;
- an anode outlet of the fuel cell stack which opens to discharge burnt anode gas inside the protective housing, whereby the burnt anode gas is mixed with a used cathode gas stream circulating inside protective housing;
- and
- an air intake for replacing a portion of the gas mixture circulating inside the protective housing with fresh gas from the outside the housing.
Dependencies are inferred from the claim text.